Chelsea must in all likelihood breach the meanest defence in Europe on Wednesday night if they are to reach the Champions League final. Atletico Madrid's back four has conceded only once in their last nine games and have the best defensive record in both La Liga and the Champions League.

At the core is Diego Godin, a man after his coach Diego Simeone's own heart who courted controversy earlier in the season when cameras spotted him appearing to encourage team-mates to hit Lionel Messi where it hurts.

The Barcelona No 10 had bent forward moments earlier with his hand across the back of his left thigh. Godin turned to team-mate Joao Miranda, pointed at the back of his own left leg and made a clenched-fist gesture that seemed to say: "He's hurt, let's finish him off." The sensitive souls over-reacted and Godin was forced into an explanation.

"They are just things you do on a football pitch," the Uruguayan said after the criticism. "I would never encourage a team-mate to injure another professional. I was just pointing out how it was the time to really keep the pressure on and take advantage because they were weakened."

Godin has faced Messi five times so far this season and the Argentine striker has still to find the net. Barcelona have only scored twice in those five games and they are not alone in being unable to break down a defence that was cobbled together by Simeone when he arrived at Atletico in December 2011.

It is easy to forget that two and a half seasons ago, the team from the other side of Madrid's Manzanares river were a pushover. They were 10th in the league, closer to the drop than the top, and Albacete from the third division had just turfed them out of the Copa del Rey. Simeone built a defence and he did not buy a single player to do it.

"Juanfran wasn't a fixture at full-back, Miranda wasn't in the team, Godin wasn't what he is now and Filipe Luis did not play," Simeone says of the squad that he inherited and transformed.

Those four were to become the best-drilled defence in Atletico's recent history with Godin – whom England must get the better of in Sao Paulo this summer when they play Uruguay – as their leader.

Alongside him, Miranda intelligently fills the gaps when Godin's will to win takes him into opposition territory. To add to their miserly record at the back, both have scored key goals for Atletico.

It was Miranda who got the winner in last season's Spanish Cup final against Jose Mourinho's Real Madrid and between them the pair have scored eight times during the current campaign.

Vicente del Bosque has even considered adopting Miranda for the Spain team in much the same way as with his Atletico team-mate Diego Costa up front. However, the defender has already represented the Brazil senior side, although he looks set to miss out on the World Cup, such is national coach Luiz Felipe Scolari's indifference towards him and his Atletico team-mate Filipe Luis.

The left-back is the third man in Simeone's mean-machine defence and probably the unit's strongest individual. He almost signed for Barcelona when he was at Deportivo but they balked at his then €20mn (£16.5m) buyout clause. He would be worth close to that now to prise away from the Vicente Calderon.

No full-back in La Liga can combine defensive strength with final-third delivery like Filipe Luis and several Premier League clubs have gone to watch Costa and midfielder Koke only to come away most impressed by the left-back.

Atletico's other full-back, Juanfran, is the final piece in the jigsaw and his rise under Simeone may be the most spectacular of all. A spindly winger who never quite made the grade at Real Madrid, Juanfran washed up at Osasuna and was eventually signed by Atletico and converted into an unconvincing emergency defender by Simeone's predecessor, Gregorio Manzano.

Simeone has turned him into the real thing, adding aggression and positioning to his attacking virtues. There are still lapses – as suffered for Spain against France last year when he gave away possession, allowing the French to equalise and complicate Spain's qualification for the World Cup – but his progress has been stellar and he will contest the right-back position this summer with the man he finds on the opposing side, Cesar Azpilicueta.

"I would rather have a lot of players who know what they are supposed to do rather than very good players," says Simeone of his style of coaching, adding: "And if you've got very good players who also happen to know exactly what they are doing then even better."

Godin, Miranda, Filipe Luis and Juanfran would now be in the second group as top defenders in their own right. Before Simeone arrived they were probably in the first category, good players in need of a brilliant coach to turn them into an unbeatable defence.